Chemical warfare agents are substances that may kill, injure or incapacitate people through their toxic effects. Of the thousands of known toxic chemicals, only about 70 have been used or stockpiled as chemical weapons in this century and only a few of these are considered suitable for use today by terrorists.(1) Nonetheless, many of these agents have legitimate alternative uses and are thus readily available from a number of sources or are relatively easy to manufacture.
Although the history of chemical weapons dates to Antiquity, their first large-scale use was during the First World War, where they caused more than 90,000 fatalities.(2) Public outrage over the use of chemical weapons in this conflict led to the signing of the Geneva Protocol in 1925, which prohibited their use in warfare, but not their production or accumulation.(3) Furthermore, several nations, including Canada, agreed to the Protocol with the following reservations: the Protocol would be binding only on relations with other Parties to the Protocol, and if any enemy state failed to observe the provisions of the Protocol, it would cease to be binding on relations with such states.(4) Nevertheless, Italy (a signatory to the Protocol) and Japan (a non-signatory nation) both used chemical weapons in Ethiopia, and in Manchuria and China, respectively. In addition, both the Allies and the Axis accumulated vast stockpiles of chemical agents during World War II, although there is no evidence these were ever deployed in this conflict.(5) Research continued on chemical weapons through the Cold War, with tremendous advances in lethality. At the same time, stockpiles continued to grow around the world. Chemical weapons were again used in the late 1980s during the Iran-Iraq war.(6) But as consensus for international disarmament grew, so did support for stronger controls on chemical weapons.
After several decades of negotiation, the Chemical Weapons Convention a new treaty designed to supplement the Geneva Protocol was opened for signature in January of 1993. Canada was among the original signatory nations and subsequently passed the Chemical Weapons Convention Implementation Act in 1995. The Convention bans all use, development, production, acquisition, stockpiling and transferring of chemical weapons. According to the Convention, chemical weapons include not only the agents themselves but also any munitions and devices designed for their dispersal.(7) The Convention defines toxic chemicals as any chemical which, through its chemical effect on living processes, may cause death, temporary loss of performance, or permanent injury to people and animals. Plants are not mentioned in this definition; as a result, the use of defoliating agents such as Agent Orange is not prohibited. Incendiary agents, such as napalm, are also not included among the agents banned by the Convention because their effects are achieved through thermal energy and not the toxic properties of the substances themselves.(8) Although prohibited for use in warfare, Riot Control Agents (RCAs) such as tear gas and pepper spray may be used domestically for law enforcement purposes under the Convention. In addition, viruses and bacteria that produce toxins are not covered by the Convention, but instead are prohibited for use as weapons under the Biological and Toxin Weapons Convention.(9)
Numerous authors have commented on the ease with which subnational organizations may acquire or produce chemical weapons. Such weapons might be:
A number of chemical agents that could potentially be used as weapons have legitimate industrial uses and may be bought from agricultural or industrial chemical supply houses.(11) For example, both phosgene and hydrogen cyanide are manufactured around the world in industrial facilities for their respective uses as a chlorinating agent and as an intermediate in acrylic polymer synthesis.(12) Several insecticides and rodenticides are widely available and highly toxic; according to some authors, these may be as dangerous as their military counterparts.(13) Because of their lower level of security, military storage facilities that house chemical agents would be much easier to penetrate than nuclear storage sites, making the theft of chemical weapons a more likely possibility.(14) Many nations, including some signatories to the Chemical Weapons Convention, have large chemical weapons stockpiles. The security of these stores varies widely both within and among states, but even in the United States some of these facilities have been described as having less security than a local supermarket.(15) Security is even more lax at medical and scientific research facilities, where both potential weapons and their precursors may be found.
Canada possesses no stockpiles of any chemical weapons other than those used for crowd and riot control purposes.(16) However, research on biological and chemical defence undertaken by the Department of National Defence (DND) at the Defence Research Establishment Suffield (DRES) requires that some stocks of agents be maintained. The DNDs research, development and training programs in biological and chemical defence are reviewed annually by the Biological and Chemical Defence Review Committee (BCDRC), to ensure that all activities within those programs are, in fact, defensive in nature and are conducted in a professional manner with no threat to public safety or the environment.(17) In its most recent report, the Committee concluded that there is no evidence of duplicity within the governments chemical and biological (CB) defence programs, nor is there evidence that offence-related programs are being conducted.(18)
Terrorist groups may also choose to produce their own chemical weapons. A decent-sized facility for the production of phosgene a chemical agent that is relatively easy to produce could be acquired for roughly $10 million to $14 million (U.S.).(19) Nerve agents are also fairly simple to manufacture; the techniques involved are similar to those used to make insecticides.(20) As mentioned earlier, a number of chemical agents may be manufactured using otherwise benign industrial facilities that already exist in many nations.(21) The ingredients used to produce many dangerous agents may have commercial applications; for example, the chemical ingredients of the nerve gas sarin are used as flame-retardants, petrol additives, plasticisers, paint solvents, ceramics and antiseptics.(22)
If a subnational group were to attempt to produce their own supplies of chemical weapons, it is generally agreed that this could be accomplished with the skills possessed by a graduate student in chemistry.(23) Much of the technical information required can be obtained from the open literature; for example, both Britain and the United States have declassified the formula for making VX nerve gas, one of the most toxic nerve agents.(24) Although agents such as sarin and VX may be manufactured with limited facilities, such an endeavour would not be totally without risk of personal injury; the inherent dangers involved in their production may be a deterrent to the use of these weapons.(25)
Greater than the challenge of producing chemical weapons is that of delivering them in an effective manner.
A terrorist attack involving chemical weapons may be obvious or covert. There are numerous ways to overtly deploy chemical weapons including bombs, submunitions, projectiles, warheads, and spray tanks.(27) Clandestine dissemination can be carried out in various ways, including the following three popular scenarios: (1) contamination of public water supplies; (2) contamination of foodstuffs; or (3) aerosol or vapour dispersal in an enclosed space.(28)
The first scenario is unlikely to succeed for several reasons. Some agents such as organophosphate pesticides break down in water, rendering them useless as weapons.(29) The filtration and purification mechanisms of most water treatment systems also help to reduce the threat of water contamination. Furthermore, because of the great volume of water in question the chemical will be highly diluted, thus an extremely large quantity of agent is necessary to successfully poison the water supply.(30) However, the water supply of an individual installation may be vulnerable to attack. In such a situation, filtration as well as dilution would be less of an obstacle to potential terrorists.(31)
There have been several documented cases involving the contamination of foodstuffs with chemical agents. Some examples include:
Aerosol dissemination of chemical weapons allows for non-explosive delivery. When using this method, enclosed spaces are ideal targets; wind direction and velocity as well as accurate weather observations are very important for a successful attack. To date, the only successful aerosol dissemination of a chemical weapon by terrorists in an enclosed space was the 1995 sarin nerve gas attack by the Aum Shinrikyo cult in the Tokyo subway. However, although this attack was intended to kill thousands, the damage was limited to 12 deaths and about 40 seriously injured people. The cult spent upwards of $30 million on research and equipment, illustrating the difficulty associated with successful mass casualty chemical weapon attacks.(32)
Chemical weapons are often divided into four groups according to the way they impact their victims. The four categories are:
Choking agents are typically dispersed as a gas and then inhaled by victims. They cause injury by attacking lung tissue and irritating the respiratory tract, including the nose and throat. Choking agents work by causing a continuous secretion of liquid into victims lungs, effectively causing them to drown.(34) Phosgene, the most dangerous of the choking agents, is the most likely candidate for future use by terrorists. Although colourless, phosgene smells similar to newly mown hay.(35)
Exposure to high concentrations of choking agents can cause death within hours but usually takes 24 to 48 hours. The symptoms of exposure during and after exposure include coughing, choking, tightness in the chest, nausea, and sometimes vomiting and headache. A symptom-free period will then follow, usually lasting from 2 to 24 hours. Thus, the symptoms of lung damage often do not manifest themselves until a few hours have passed and they are aggravated by physical exertion. Rest and medical observation are therefore essential.(36) Coughing, rapid shallow breathing, cyanosis and possibly nausea and vomiting characterize the onset of the pulmonary edema, which is what actually kills victims. As the pulmonary edema progresses, a frothing sputum develops.(37) If the victim survives more than 48 hours, he/she will usually recover. In these cases, the patient usually recovers with little or no residual damage. All contact with these agents should be avoided, specifically through the use of protective clothing, and breathing and eye protection.(38)
Blister agents, also referred to as vesicants, are some of the most common chemical weapons; they include mustard agents, Lewisite and phosgene oxime. Vesicants initially irritate, then cause damage to their victims eyes, respiratory tract and skin.(39) These agents burn and blister any part of the body they come into contact with, predominantly the skin, but also the eyes, mucous membranes and lungs. When inhaled, vesicants harm the respiratory tract; when ingested, they can cause vomiting and diarrhea.(40) Although only a small percentage of blister agent victims die, blindness and permanent respiratory system damage are common. Blister agents can be dispersed as a liquid, aerosol, vapour or dust.(41)
Mustard agents are characterized by a latent symptom-free period, which usually lasts several hours, depending on the quantity of agent involved, the mode of exposure and environmental conditions.(42) As a result, exposure may initially go unnoticed. In contrast, Lewisite and phosgene oxime both work quickly; symptoms, such as coughing and burning, appear almost immediately. Like mustard agents, Lewisite provokes severe irritation of the respiratory tract, and the dead tissue that results may obstruct the victims airway; victims are also predisposed to secondary infection because of the damage sustained.(43) Few compounds are as painful and destructive as phosgene oxime; only a few milligrams are needed to inflict severe wounds, and recovery may take up to three months.(44)
Dispersed as a gas, blood agents enter the body by inhalation and are then distributed through the body via blood. They act to inhibit blood cells from using and transferring oxygen, thereby depriving the body of oxygen and essentially causing the victim to suffocate.(45) Symptoms include abdominal pain, nausea, vomiting, dizziness, headache, confusion, weakness, drowsiness, unconsciousness, burning sensation, sore throat, shortness of breath, and coughing.(46)
The emergence of symptoms of infection by blood agents may be delayed. For example, exposure to arsine or cyanogen chloride can lead to severe lung, eye and skin damage, but these may not manifest themselves for several hours.(47) Arsine may also impair kidney performance, while hydrogen cyanide can damage the central nervous system causing the victims circulatory and respiratory systems to malfunction.(48) Individuals may avoid contact with these agents through the use of protective clothing as well as breathing and eye protection.
Nerve agents may be dispersed as a liquid, vapour, aerosol or dust. By interfering with the normal function of acetylcholinesterase (an enzyme important to the working of the nervous system), nerve agents impair the victims muscles.(49) These agents also work quite rapidly; a lethal dose may cause death in as little as five minutes.(50) Symptoms of nerve agents will usually follow the route of exposure. For example, when the agent is inhaled, respiratory symptoms emerge first; when ingested, the first symptoms will be gastrointestinal.(51)
Nerve agents known as G-agents such as tabun, soman, cyclosarin and sarin tend to be short-lived once released, lasting only a few days; however, V-agents of which VX is the most widely known will persist in the field for longer periods of time, up to several months in very cold conditions.(52) Symptoms are uniform for all types of nerve agents; they include runny nose, watery eyes, drooling and excessive sweating, tightness of the chest, difficulty breathing, dimness of vision (pupils become pinpointed), nausea, vomiting, cramps, loss of bladder or bowel control, twitching, jerking and staggering, headache, confusion, drowsiness, coma and convulsions.(53) Full protective clothing and respiratory protection are necessary to avoid exposure to nerve agents. Antidotes to nerve agents do exist and are stocked by some ambulance teams and hospitals, but because nerve agents work so quickly, these are only effective if introduced immediately after exposure.(54)
The use of chemical weapons is generally associated with the technological advances that created modern warfare in the 20th century. The U.S. Army first used the term chemical warfare in 1917 to describe tactical warfare using incendiary mixtures, smokes, or irritant, burning, poisonous, or asphyxiating gases. By the end of World War I, the situation had changed drastically. Chemical weapons had been used extensively, and a new convention was being negotiated to reduce its use and development. However, the use of poison and disease in war, against soldiers and civilians alike, dates back much further. Below is a timeline of some key points in the history of chemical warfare.(55)
(1) Organisation for the Prohibition of Chemical Weapons (OPCW), Chemical Warfare Agents, 1997. The States Parties to the Chemical Weapons Convention set up the OPCW to oversee the implementation of its provisions.
(2) OPCW, A Brief History of Chemical Disarmament, 1999. For more information on the history of chemical weapons development and use, please refer to the History of Chemical Warfare section at the end of this paper.
(4) William H. Barton, Research Development and Training in Chemical and Biological Defence within the Department of National Defence and the Canadian Forces, National Defence Canada, 31 December 1988.
(5) OPCW (1999), A Brief History of Chemical Disarmament.
(7) The full text of the Convention may be found on the Department of Foreign Affairs and International Trade website.
(8) OPCW (1997), Chemical Warfare Agents.
(10) Ron Purver, Chemical and Biological Terrorism: The Threat According to the Open Literature, CSIS, 1995.
(13) Purver (1995).
(15) Richard Charles Clark, Technological Terrorism, Devin-Adair,Old Greenwich, CT, 1980, as cited by Purver (1995).
(16) National Defence, Canadian Forces Operations: Nuclear, Biological and Chemical Defence, B-GG-005-004/AF-011.
(17) Heather D. Durham (Chair), Colin R. McArthur and Kenneth L. Roy, 2000 Annual Report of the Biological and Chemical Defence Review Committee, September 2000, p. C-1.
(18) Ibid., p. 2.
(19) Pike (1998), Chemical Weapon Production.
(20) Elliott Hurwitz, Terrorists and Chemical/Biological Weapons, Naval War College Review, 35:3 (May-June), 1982, pp. 36-40, as cited by Purver (1995).
(21) Pike (1998), Chemical Weapon Production.
(23) Purver (1995).
(26) R.W. Mengel, Terrorism and New Technologies of Destruction: An Overview of the Potential Risk, Appendix 2, in: Disorders and Terrorism: Report of the Task Force on Disorders and Terrorism, National Advisory Committee on Criminal Justice Standards and Goals, Washington, D.C., 1976, pp. 443-473, as cited by Purver (1995).
(28) Purver (1995).
(32) The terror next time? (2001).
(33) Approximate median lethal dosage of inhaled airborne agent given in LCt50 (milligrams per minute per cubic metre, or mg-min/m3), also referred to as lethal concentration time. Approximate median lethal dosage of skin-absorbed agent given in LD50 (milligrams of agent per kilogram of body weight, or mg agent/kg body weight). The lower the number, the more lethal the agent.
(34) OPCW (2000), Fact Sheet 4: What is a Chemical Weapon?
(37) Pike (1998), Chemical Warfare Agents.
(38) IPCS & CEC (1993), Phosgene, International Chemical Safety Cards.
(39) OPCW (2000), Fact Sheet 4: What is a Chemical Weapon?
(40) Pike (1998), Chemical Warfare Agents.
(41) OPCW (2000), Fact Sheet 4: What is a Chemical Weapon?
(42) Pike (1998), Chemical Warfare Agents.
(45) OPCW (2000), Fact Sheet 4: What is a Chemical Weapon?
(46) International Programme on Chemical Safety & the Commission of the European Communities, Arsine, Cyanogen Chloride, Hydrogen Chloride, Hydrogen Cyanide, Liquefied, International Chemical Safety Cards, 1993.
(47) International Programme on Chemical Safety & the Commission of the European Communities, Arsine, Cyanogen Chloride, International Chemical Safety Cards, 1993.
(48) International Programme on Chemical Safety & the Commission of the European Communities, Hydrogen Cyanide, Liquefied, International Chemical Safety Cards, 1993.
(49) Pike (1998), Chemical Warfare Agents.
(50) OPCW (2000), Fact Sheet 4: What is a Chemical Weapon?
(51) Pike (1998), Chemical Warfare Agents.
(55) Sources used to compile timeline: